Data coverage and freshness

Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

Beyond the read-only/idempotent annotations it discloses non-obvious traits: counts are approximate planner estimates rather than exact tallies, the freshness field is event-weighted over the trailing 30 days, and there are no key or quota costs. It even points to the equivalent resource borme://coverage.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

Front-loaded purpose, then usage, then return shape, then access notes — a sensible order with no filler. Slightly long for a single-purpose stats call, and the example value '(e.g. 0.9987)' is borderline unnecessary.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

With no output schema, the description compensates by enumerating every returned field and its meaning, including the approximate nature of counts and the date format. Nothing an agent needs to interpret the result is missing.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Zero parameters gives a baseline of 4; the description reinforces this with 'Takes no arguments,' which removes any doubt about whether a date range or filter can be supplied. No further parameter meaning is needed.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

States a specific verb+resource ('Report the coverage and freshness of the BORME data') and draws an explicit boundary against the sibling search tools: 'it says nothing about any one company.' An agent can place it among search_companies/search_events/company_* without ambiguity.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

Gives concrete triggering questions ('how much data is there?', 'how fresh is it?', 'can I trust date filters for period X?') and a sequencing rule: call it before running searches. It also names what it is not for.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.